In recent years, video tape recorders (VTRs) are made available in reduced sizes. Especially, subminiature lightweight VTRs have been realized for use with a magnetic tape having a width of 8 mm.
With a reduction in the size and weight of VTRs, a camera-equipped VTR has been realized which comprises a VTR unit and a camera unit attached thereto. It is also possible to provide a liquid-crystal color television and a VTR in the form of an assembly to realize a portable image reproduction system. Stringent requirements are made of such VTRs for further miniaturization.
A VTR has been proposed which is variable in depthwise length along the direction of insertion of the cassette according to the mode of its operation as seen in FIGS. 39A and 39B (Unexamined Japanese Patent Publication SHO 61-271648).
With the proposed VTR, a cylinder device 14 having a rotary magnetic head is mounted on a main chassis 1, and a reel chassis 4 provided on the main chassis 1 is slidable toward or away from the cylinder device 14. A supply reel support 43 and a take-up reel support 44 are mounted on the reel chassis 4.
In the mode (standby mode) illustrated in FIG. 39A, the reel chassis 4 is partly projected from the main chassis 1 as indicated at A. A tape cassette 9 is placed on the reel supports 43, 44 on the reel chassis 4 in this state.
In the mode (play mode) shown in FIG. 39B, the reel chassis 4 is positioned as slidingly shifted toward the cylinder device 14, with the cylinder device 14 partly inserted in the front opening 91 of the cassette 9. In this state, the magnetic tape is passed around the cylinder device to record signals on the tape or reproduce signals therefrom.
The VTR is convenient to carry since the depthwise length can be reduced from L.sub.1 to L.sub.2 as illustrated.
With the VTR, however, the minimum depthwise length L.sub.2 is limited by the size of the cassette, imposing a limitation on the miniaturization of the apparatus. For example, when the cylinder device 14 for an 8-mm VTR is 27 mm in outside diameter, the minimum depthwise length L.sub.2 is virtually limited to about 85 mm. Furthermore, standards or specifications are set for 8-mm VTRs in respect of the cassette size and the outside diameter of the cylinder device 14. Accordingly, difficulties are encountered in subminiaturizing the VTR.
Unexamined Japanese Patent Publication SHO 62-164249 discloses a VTR wherein the cylinder device 14 can be almost completely accommodated in the opening 91 of a cassette 9 in the play mode in order to reduce the depthwise length in this mode. The apparatus is so adapted by accommodating in the cassette 9 a magnetic tape having a shorter length than the standard to reduce the diameter of the reels therein and to correspondingly enlarge the opening 91. The VTR therefore has the drawback of being unusable for the standard cassette.